German Patent 28 30 552 with the title "Safety means against short circuiting of an electric ignition means" should be noted.
It is already known to provide a releasable connector assembly between an ignition cable of an ignition control means and an airbag restraint or safety apparatus comprising an igniter. As is known, the igniter is used for igniting a gas generating charge (within said restraint apparatus) which, in turn, causes the deployment of the airbag (gas bag). Typically, the ignition of the igniter is caused by an electrical ignition signal which is supplied to the igniter from said ignition control means via said ignition cable. Thus, the ignition cable is connected to said ignition control means which generates the ignition signal in case the deployment of the airbag is required.
Commonly, the ignition cable leading to the restraint apparatus comprising the igniter is provided with an ignition cable connector preferably of the plug-type which can be coupled or plugged into an apparatus connector preferably of the jack or socket-type in a releasable manner. Said apparatus connector forms part of said restraint apparatus and of a unit thereof which might be referred to as an ignition generator. Generally speaking, the igniter and said apparatus connector are commonly arranged in a housing (ignitor support) of said ignition generator.
Below, referring to FIGS. 1 through 9 a known ignition cable connector as well as a known ignition generator will be described together with a respective apparatus connector.
It is already known to provide within the apparatus connector a so-called short circuit bridge means, so as to avoid an unintentional ignition of the ignition generator at a point in time where there is not yet provided the proper connection with the ignition cable connector. Said short circuit bridge means is adapted to provide a short circuit for the contact pins (there are generally two pins) of the apparatus connector of the ignition generator at a time when the ignition cable connector is not yet in engagement with the apparatus connector. When the ignition cable connector is brought into engagement with or inserted into the apparatus connector, then the short circuit bridge means is interrupted due to the fact that (two) contact springs or arms (contact spring arms) of the short circuit bridge are lifted from the respective contact pins. Said lifting of the contact arms is carried out by means of a projection or nose formed on said ignition cable connector. Said nose is provided with contact bushings or sleeves adapted for cooperation with the contact pins of the apparatus connector. Provided the nose is sufficiently inserted into the apparatus connector, then said contact arms will be lifted and, in addition, detent or locking means provided at said nose will come into locking engagement with counter detent or locking means which are provided in an insulating body of the apparatus connector.
It was recognized that for the above connector assembly an undesirable situation can occur if the nose is not completely inserted into the apparatus connector. Under these circumstances, see FIG. 8, the contact arms adapted to cause the short circuit, are lifted and the contact sleeves of the ignition cable connector are in contact with the contact pins of the apparatus connector, but no locking of the nose has yet occured so that, for instance, during operation of the vehicle using the restraint apparatus the vibrations of the vehicle might cause the nose and thus the entire ignition cable connector to separate from the apparatus connector (a counter connector) with the consequence that a critical situation occurs insofar as the airbag cannot be deployed which might lead to damages for the vehicle occupant.
It is an object of the present invention to provide for a connector assembly or system which is characterized by a well-defined locking effect providing for a sufficiently high holding force (which is for instance larger than 100N).
It is another object of the present invention to provide for an ignition cable connector which assures that the short circuit contact arms will only be opened if the ignition cable connector is safely locked at or in the apparatus connector.
It should be added that for the critical situation described above with a not properly locked ignition cable connector a diagnosis test would show that the restraint apparatus comprising the airbag is operative in as much as the short circuit contact arms are lifted, with the possible consequences referred to above.
So as to attain the above objects and to avoid the disadvantages of the prior art, the present invention provides for a defined locking between the two connectors of the connector assembly, i.e. specifically between the ignition cable connector and the apparatus connector.
In accordance with a preferred embodiment of the invention said defined locking effect is provided by integrated locking means at the ignition cable connector as well as by counter locking means at the connector of the ignition generator, i.e. the apparatus connector. Said locking means as well as said counter locking means being adapted to cooperate to provide a positive locking between said ignition cable connector and said apparatus connector. Said locking means are preferably in the form of locking hooks. Preferably said locking hooks are integrally formed integrated in the ignition cable connector and arranged such that they can only be released from said counter locking means by a respective tool.
In accordance with another embodiment of the invention the operation of the connector assembly of the invention can be further improved by providing push or inertia generating means which will make sure that the ignition cable connector will reach its proper operating position with the proper locking effect being provided in said operating position. Said desired push or inertia effect will be obtained when inserting the ignition cable connector into the apparatus connector by providing a pressure point-cam-locking means between the nose of the ignition cable connector and a receiving opening of an insulating body of the apparatus connector. In accordance with the invention and different from the prior art, this is achieved by placing the pressure point of the nose (which can also be called a plug nose) forwardly. As a consequence of this arrangement a safe opening of the short circuit contact arms is only achieved if the ignition cable connector is properly and safely inserted (i.e. plugged into the apparatus connector) and is in its detent or preferably locking condition.
Inasmuch as gas generators are manufactured in large numbers, significant changes of the ignition generator are not possible. This makes the solution of the above outlined problem difficult.
By arranging the locking means in accordance with the invention at the ignition cable connector not only a defined locking effect of the ignition cable connector at the apparatus connector is achieved, it is further possible to check the existence of a proper connection of the connector assembly simply by visual inspection and control.
Further advantages, objects and details of the invention can be gathered from the description of embodiments of the invention disclosed in the attached drawings.
FIGS. 1 through 9 disclose a connector system of the prior art comprising an ignition cable connector and an apparatus connector.
FIG. 1 is a bottom view of an ignition cable connector of the prior art;
FIG. 2 is a side elevational view of the connector of FIG. 1, partly in cross section;
FIG. 3 is a rear view of the ignition cable connector of FIG. 1, partly in cross section;
FIG. 4, 5 and 6 are different views of a prior art insulating ring having a short circuit bridge, said insulating ring being adapted to be inserted into the ignition generator shown in FIG. 7;
FIG. 7 is a side elevational view of an ignition generator, partly in cross section, comprising an apparatus connector adapted to receive said ignition cable connector;
FIGS. 8 and 9 are sectional views (offset by 90.degree.) of a part of the connector assembly represented by the ignition cable connector of FIG. 2 and the apparatus connector of FIG. 7, with said connectors being partially engaged.
FIGS. 10 and 11 correspond to FIGS. 20 and 21 of the first embodiment of the invention; said FIGS. 10 and 11 being shown here adjacent to the prior art of FIGS. 8 and 9 to enhance the understanding of the invention.
FIGS. 12 through 23 refer to a first embodiment of the present invention disclosing the locking means of the invention as well as the push or inertia generating means.
FIG. 12 discloses an initial phase of the insertion of an ignition cable connector into an apparatus connector, with said connectors being shown in cross section along line A--A in FIG. 1 (as far as the prior art is concerned);
FIG. 13 is the initial phase shown in FIG. 12 in a partial sectional view similar to FIG. 12, however, with the sectional line being rotated by 90.degree. with respect to the sectional line A--A;
FIGS. 14 and 15 and likewise FIGS. 16 and 17 and FIGS. 18 and 19 as well as FIGS. 20 and 21 disclose intermediate stages of the insert operation of the ignition cable connector into the apparatus connector;
FIGS. 22 and 23 disclose the final stage of the insertion where the ignition cable connector and the apparatus connector are in engagement and properly locked to each other;
FIG.19a is an enlargement of FIG. 19;
FIG.23a is an enlargement of FIG. 23.
FIGS. 24 through 35 disclose a second embodiment of the invention, which is a simplified version of the first embodiment in so far, as the push or inertia effect generating means are not present, but only the locking means; Otherwise, the representations of FIGS. 24 through 35 are similar to the representations of FIGS. 12 through 23, and thus no additional explanations are necessary.
FIG. 36 is a sectional representation of the connector assembly of the second embodiment of the invention where the ignition cable connector is inserted into an apparatus connector, and where a de-locking tool is inserted to show the operation of de-locking the connector assembly;
FIG. 37 is a top plan view of the ignition cable connector of FIG. 36 with the tool not being shown;
FIG. 38 is a sectional view similar to FIG. 36, however, with the de-locking tool not being inserted;
FIG. 39 is a perspective view of a detail of the locking means in the form of a locking or detent hook shown in FIG. 38;
FIG. 40 is a top plan view of the ignition cable connector of the second embodiment with an insulating housing upper part being removed;
FIG. 41 is a sectional view of a third embodiment of the ignition cable connector; and
FIG. 42 is a top plan view of the ignition cable connector of FIG. 41.